US 4,762,447 AGranted

Dual-plane high-speed collet

AssigneeOptima Industries, Inc.

InventorWilliam F. Marantette

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Abstract

The collet includes a compressible basket having a central opening to receive a tool shank and two exterior surfaces tapering in opposite directions. One tapered exterior surface engages a matching tapered interior surface of a hollow rotatable shaft that receives it. The other tapered exterior surface engages a matching tapered interior surface of a wedge received in the shaft and movable axially relative to it. The angles of the tapers are such that they are self holding. The collet is closed by moving the wedge which compresses the basket sequentially at the two tapered surfaces, locking the tapers. The force on the wedge is released after this, leaving the tapers locked without external force as the tool is gripped in two locations during operation of it. The collet is actuated by a pneumatic power cylinder with two pistons having portions that engage an extension of the wedge for moving it, after which these portions are spaced from the wedge extension so that they do not interfere with the operation of the tool. The position of the power cylinder is adjustable to assure clearance at the wedge extension.

Claims28

Dependent claims

A collet comprising

a radially-compressible member having an opening adapted to receive the shank of a rotatable tool,
said radially-compressible member having a first tapered exterior surface, and a second tapered exterior surface spaced from said first tapered exterior surface,
a first means having a tapered surface engaging said first tapered exterior surface,
a second means having a tapered surface engaging said second tapered exterior surface,
the angles of the tapers of all of said tapered surfaces in interengagement being matching and that of self-holding tapers,
said radially-compressible member being movable relative to said second means, said first means being movable relative to said radially-compressible member and said second means,
means for applying a first force in one direction on said first means such as to cause said first means to move relative to said second means and said radially-compressible member in one direction so as to cause said tapered surface of said first means to react against said first tapered exterior surface and compress said radially-compressible member around the shank of such a tool so as to grip said shank at a first location, and to cause said tapered surface of said first means and said first tapered exterior surface to frictionally lock together, and thereafter to cause said first means to move said radially-compressible member relative to said second means in one direction so as to cause said tapered surface of said second means to react against said second tapered exterior surface and compress said radially-compressible member around the shank of such a tool so as to grip said shank at a second location, and to cause said tapered surface of said second means and said second tapered exterior surface to frictionally lock together,
means for thereafter releasing said first force to allow said tapered surfaces to remain so locked and said radially-compressible member to grip said shank at two locations, whereby such a tool can be operated without an external force on said radially-compressible member, means for applying a second force in the opposite direction to cause relative movement of said radially-compressible member and said first means in the opposite direction and to cause relative movement of said second means and said radially-compressible member in the opposite direction, thereby to unlock said tapered surfaces and release said shank, and
means for thereafter releasing said second force to allow said tapered surfaces to remain unlocked.

6 more elements

A device for gripping and rotating a tool comprising a rotatable shaft having an axial opening extending inwardly from one end thereof,

said opening being defined by a tapered surface adjacent and tapering toward said one end, and a cylindrical surface inwardly of said tapered surface,
a basket of resilient material received in said opening,
said basket having
a cylindrical opening extending therethrough adapted to receive the shank of a tool,
a first tapered exterior adjacent one end thereof and adjacent and engaging said tapered surface of said shaft, the taper of said first exterior surface matching the taper of said tapered surface of said shaft,
a second tapered exterior surface adjacent the opposite end thereof, said second exterior tapered surface being adjacent and spaced from said cylindrical surface and tapering in a direction opposite from that of said first exterior tapered surface,
and a plurality of slots extending through said basket whereby said basket is radially compressible,
a wedge member of resilient material received in said opening in said shaft,
said wedge member having a portion having
a cylindrical exterior surface adjacent and engaging said cylindrical surface of said opening,
a tapered interior surface adjacent and engaging said second tapered exterior surface, the taper of said interior surface of said wedge member matching the taper of said second tapered exterior surface,
and a plurality of slots extending through said portion of said wedge member, whereby said portion of said wedge member is radially expansible,
the angles of all of said tapered surfaces which are in interengagement with each other being such that the tapers are self holding, and
force means movable from a position remote from said wedge member to a position of engagement therewith for applying a force to said wedge member to cause movement thereof toward said one end of said shaft so that said tapered interior surface of said wedge member slides along said second tapered exterior surface of said basket as said exterior surface of said wedge member is confined by said cylindrical surface of said shaft, thereby to compress said basket locally and grip at one location the shank of a tool received in said cylindrical opening in said basket, and to cause movement of said basket relative to said shaft so that said first tapered exterior surface slides along said tapered interior of said shaft, thereby to compress said basket locally and grip at a second location the shank of such a tool,
said force means being thereafter movable to a position remote from said wedge member for leaving said interengaged tapered surfaces frictionally locked and gripping said shank in two locations without the application of an external force.

12 more elements

The method of gripping and operating a tool comprising the steps of

providing a radially-compressible member having a cylindrical opening adapted to receive the shank of a tool, a first exterior surface tapering in one direction and a second exterior surface tapering in the opposite direction,
providing a rotatable shaft having an opening therein receiving said radially-compressible member, with said opening being provided with a tapered surface engaging and at the same angle as said first exterior surface so as to provide a first pair of matching tapers,
providing a second member having an opening therein having a tapered surface having the same angle of taper as that of said second exterior surface,
positioning said second exterior surface within said opening in said second member adjacent said tapered surface thereof so as to provide a second pair of matching tapers,
the angles of the tapered surfaces of said first and second pairs of matching tapers being such that said tapers are self-holding,
positioning the shank of a tool within said cylindrical opening,
then applying a force to said second member so as to move said second member axially in one direction relative to said radially-compressible member for causing said tapered surface of said second member to react against said second exterior surface so as to compress said radially-compressible member adjacent thereto for gripping said shank at one location, and thereafter causing said second member to move said radially-compressible member axially in one direction relative to said shaft so that said first exterior surface reacts against said tapered surface of said shaft and said radially-compressible member is compressed adjacent thereto for gripping said shank at a second location,
and then removing said force from said second member so that said first and second pairs of matching tapers remain frictionally locked together without the application of an exterior force and said shank continues to be gripped in said two locations,
and then rotating said shaft and with it said shank for causing operation of said tool.

6 more elements

Dependencies are inferred from the claim text.